Originally Posted by
MHultgren
Layer manager has been a cause for lags for the past few releases along with the Hardware Accelerator turned on. The new version of the layer manager can be changed back to the 'legacy' style by using the LAYERDLGMODE variable (1=new). And don't forget to close your Properties Palette whenever you are not using it. Another thing to watch out for is using running Osnaps and moving your mouse across a surface or alignment/corridor will cause a lag while C3D tries to find the various Osnaps for the entities.
Just a few tips from personal use for the past eight years.